This invention relates to certain 2'-F, 2-halo substituted purine nucleosides.
Certain arabinofuranosyl nucleosides have well known antiviral (araA) and anticancer (araC) activity. Some arabinofuranosyl nucleosides with 2'-substituents other than a hydroxyl also have shown useful biological effects. All of these nucleosides require activation (phosphorylation) to be effective, and generally this is accomplished by different enzyme than the corresponding ribofuranosyl nucleosides.
U.S. Pat. No. 4,751,221 to Watanabe et al discloses nucleosides represented by the following formula: ##STR2## wherein
X and Y are the same or different and are hydrogen, OR.sup.3 (keto or enol), SR.sup.3, NR.sup.3 R.sup.4, NH acyl or halogen such as chlorine or bromine;
R.sup.3 and R.sup.4 are the same or different and are hydrogen, lower alkyl of 1 to 7 carbon atoms such as methyl, ethyl, propyl and the like, aralkyl such as benzyl, benzhydryl, p-methoxybenzyl and the like, or aryl such as phenyl, p-chlorophenyl, toluyl, p-methoxyphenyl, naphthyl and the like;
NH acyl may be an alkanoyl or aroyl amide; and
R.sup.1 and R.sup.2 are the same or different hydrogen or acyl groups which may be alkanoyl groups of 1 to 20 carbon atoms such as formyl, acetyl, propionyl, isopropionyl, butyryl, isobutyryl, tert-butyryl, valeryl, pivaloyl, caproyl, capryl, lauryl, myristyl, palmityl, stearyl, arachidyl, stilligyl, palmitoleyl, oleyl, linolenyl, arachidonyl and the like.
Montgomery et al, Journal of Medicinal Chemistry 1986, Vol. 29, No. 11, pps. 2389-2392 disclose nucleosides having the following formula: ##STR3## wherein R.sup.1 and R.sup.2 are the same and may be Cl or NH.sub.2, R.sub.3 may be benzoyl or hydrogen, and R.sub.4 may be acetyl or hydrogen.